Control system for flying shears



Dec. 11, 1934. F c E ]R 1,984,051

CONTROL SYSTEM FOR FLYING SHEARS Filed Sept. 6, 1935 -GOOOOG j ZINVENTOR Wl.TNE-S$'E6 z Patented Dec. 11, 1934 UNITED STATES PATENT OFFICE United Engineering & Foundry Company,

Pittsburgh, Pa., a corporation of Pennsylvania Application September 6, 1933, Serial No. 688,323

' 12 Claims.

This invention relates to a control system, and more particularly to an electroresponsive system for automatically regulating the feeding of web material or the like into a flying shear or similar work device.

An object of the invention generally stated is to provide for automatically controlling the feeding of Web material, such as metal strips, bars, sheets, and the like, into a continuously operated flying shear or similar work device, and for accurately synchronizing the movement of the material with the movement of the shear.

A more particular object is to provide for automatically controlling the entrance of the leading end of a piece of web into a flying shear in timed relation with the movement into cutting opposition of cutting blades of the shear for cropping purposes, and for doing so in such a way as to accurately determine the amount of material removed by the first cut without altering or interfering with the subsequent cuts, which is highly desirable, particularly in the cutting of various kinds of metal stock.

These and various other objects, as well as the various other novel features and advantages of the invention, will be fully appreciated when the following detailed description is read in conjunction with the accompanying drawing, of which Fig. 1 is a schematic illustrationof a. single ern bodiment of the invention as applied to a flying shear, and Fig. 2 a plan view of the shear and feed table shown in Fig. 1.

Referring in detail to the drawing, the numeral 1 designates a. flying shear which, although it may be any suitable form of shear, is illustrated as one of the rotary type comprising a pair of'drum-like carriers 2 and 3 on which a. plurality of equally spaced-cutting blades 4, 5 and 6 are provided. For actuating these carriers, they are connected to a motor 7, and for feeding the matori'al'to be severed, such as the strip 8, into the shear, a roll-table 9 or other suitable feeding means is mounted in front of the shear 1, beingequipped with a driving motor 11.

According to the invention, the feeding mechanism, and in the present embodiment the roll table 9, is utilized for regulating theentrance of the stock 8 into the shear, such being accomplished by varying the speed of the table to synchronize the entrance of the stock into the shear with the movement into cutting opposition of theshear blades. To provide for varying the speed of the table, a variable speed driving motor 11 is employed and preferably one of the direct GUI- rent type, although any suitable regulable motor may be utilized for this purpose. i

For controlling the operation of the feed motor 11 so as to synchronize the entrance of the leading end of a piece of stock being fed into the shear with the movement into cuttingopposition' of the shear blades, a series of light-responsive devices, such as selenium cells 12, 13, 14 and 15, is arranged below the path of the strip 8. Above these devices, and in vertical alignment with them, a series of lamps 16, 1'7, 18 and 19.is. arranged, being supported in any suitable manner directly over the path of the stock so that the rays of light produced by them will be intercepted by the stock as it passes between them and the cells 12, 13, 14 and 15. For a purpose which will presently appear these lamps and light-responsive devices are arranged some distance from the shear 1 and uniformly spaced along a length of the roll table which is equivalent to the distance between successive cutting blades on the shear or the distance which the table normally feeds the stock between cuts. I

For energizing the,system, a source of current supply represented by line conductors L1 and L2 is provided. To these line conductors the lamp 16, which is spaced farthest from the shear 1, is connected by a pair 01' conductors 21 and 22 for continuous illumination. The light cell 12 associated with this lamp is connected to the supply conductors L1 and L: by a pair of conductors 23 and 24, and adapted to-function as a sort of start and stop control for the rest of the system, being of the type which closes the circuit 25 controlled by it when the light to it from the lamp 16 is shut off by the strip 8 as the strip approaches the shear. This circuit, as shown, is traced through the actuating coils 26a of a normally open double pole contactor 26 and connected to the line conductors L1 and L2. One pole 26b of such contactor is adapted to control a circuit 27 by which the other 'lamps 1'7, 18 and 19 of the system are connected. to the source of current supply L1 and L2 in series circuit relation with an interrupter switch 20 which is coupled to the shear. The other pole 260 of this contactor is adapted when closed to establish a shunt circuit 28 about one of the operating coils 29a of a time delay relay 29.

This relay 29, while it may take numerous other forms, is, as shown, one of the residual magnetism delaying type, a form of relay which it is believed is sufliciently well known in theart as not to require any specific detailed description. As illustrated, it consists of an armature 29b on which two opposing coils 29a and 290 are mounted and its energy can be dissipated. As soon as the force produced by this field falls below the force produced by the field of the lower coil 29c, the relay opens, the operation requiring a period of time determined by the characteristics of the two coils, and their magnetic circuits which, as will be appreciated by those skilled in the art, may be changed by changing the characteristics of such coils and their magnetic circuits.

The bridging member 29d of the relay 29 is employed to complete a series of holding circuits 33a, 33b'and 330' for the actuating coils 34a, 35c: and 36a, of a series of normally closed contactors 34,35 and 36 which are employed to control a series of shunt circuits 37', 38 and 39 provided about a series of resistors 41, 42 and 43, respectively, that are in turn connected in a circuit 44 by which the field windings 11a of the table motor 11 are connected to the source of current supply L1 and L2 and utilized for varying the field of such motor to thereby vary the speed of the feed table. As illustrated, the actuating coils 34a, 35a. and 36a. of the contactors 34, 35 and 36 are connected by separate circuits 45, 46 and 4'7 to the source of current supply L1 and L2 through the light cells 13, 14 and 15 which are themselves connected in parallel relation to the circuit 23 and utilized to control the operation of these contactors, being adapted to close the shunt circuits and cause the contactors 34, 35 and 36, respectively, to open whenever the rays of the lamps 17, 1 8 and 19 are projected upon them. Consequently, as the lamps 1'7, 18 and 19 are illuminated by the interrupter switch 20, which isenergized as soon as the contactor 26 is closed by the stock passing under the first lamp 16, these cells 13, 14 and 15 are rendered responsive for closing the circuits 44, 45 and 46, which control the actuation of the contactors 34, 35 and 36, and they in turn the opening of the shunt circuits 41, 42 and 43.

The interrupter: switch 20, which is connected in series circuit relation with the lampsl'l, 18

and 19, as shown, comprises a distributor ring 48.

made of insulating material which is mounted in any suitable fashion for rotation with the shear. In the periphery of this ring there are arranged conductor segments 51, 52 and 53, equaling in number the number of blades on the shear drums, and equally spaced. To these segments the one side of the lamp circuit 2'? is connected, while the other side is connected by a collector brush 54 disposed to ride on the ring 48 and a conductor 55 to the line conductor L2. Hence, the lamps 17,

18 and 19 are in this way caused to flash each under the brush 54 as long as the circuit 27 is closed, and these segments are arranged to engage the brush 54 at the same time or in timed relation with the movement of the shear blades into cutting opposition.

As will be appreciated, the extent to which the operation of the feed table 9 must be modified to get the end of each piece of stock in step with the shear to produce the length of first cut de- 43 in the field circuit 44 of the table motor.

sired is determined by the extent to which the stock is out of step with the shear when it is delivered to the feed table, and is equal to the distance the stock is fed past the first light-responsive device 12 before the lamps 17, 18 and 19 are flashed which, as stated hereinbefore, is effected by the interrupter switch when the blades of the shear move into cutting opposition. It is for the purpose of measuring this and controlling the modification of the feed table speed that the light-responsive devices 13, 14 and 15 are provided, and while only three are shown here, it will be readily understood that any reasonable number may be employed for such purpose.

As will be also readily appreciated, the feed table may be either slowed up or speeded up to get the stock in step with the shear, although the latter method is practiced in the present embodiment. According to this embodiment the resistors 41, 42 and 43 are so proportioned and the time delay relay 29 so adjusted that they automatically vary the speed of the table sufiiciently to make the corrections in the delivery of the stock to the shear required as is determined by the operation of the light-responsive devices 13, 14 and 15. To prevent this irregular operation of the stock feed frominterfering with the subsequent cuts made by the shear, these control devices are of course spaced sufliciently far enough away from the shear so that the correction is completely made and the table returned to its normal operating speed before the stock reaches the shear.

By way of describing the operation of the system, assume that the shear is being run at a constant speed which it normally is, although it may be varied as desired by any suitable means, not shown, and that the feed table is being operated at a constant speed as it also normally will be, although, as shown, a variable resistor 56 may be included in its field circuit 44 for manually varying its normal speed. In addition, assume that a piece of stock 8 is loaded at random onto the table. As the front end of such stock passes over of the contactor 26. With the closing of this conv tactor the circuit 27 to the shear operated interrupter switch which controls the flashing of lamps 17, 18 and 19 is closed and also the circuit 28 which shunts the upper coil 29a of the time delay relay 29. The closing of the former circuit to the interrupter switch results in the lamps above the light-responsive devices 13, 14 and 15 being flashed when the first set of blades on the shear moves into cutting opposition, and the closing of the latter sets the time delay relay into operation to open the holding circuits 33a, 33b and 330 for the contactors 34, 35 and 36 which control the resistors 41, 42 and 43.

Shouldthe lamps 1'7, 13 and 19 flash before the stock 8 reaches the second light-responsive device 13, all of the devices 13, 14 and 15 will operate and cause all of the contactors 34, 35 and 36 to close. These in closing open the circuits 3'1, 38 and 39 and place all of the resistors 41, 42 and They also close the circuits 33a, 33b and 330 which hold the contactors 34, 35 and 36 closed. Consequently even after the lamps 1'7, 18 and 19 become dark, which causes the devices 13, 14 and 15 to open, the resistors are maintained in the field circuit until the time delay relay opens. This occurs only after these resistors have been in the field circuit long enough to cause the stock to be advanced an amount over that which it is when the feed table is at its normal speed, which is equal to the extent it is out of step with the shear.

In the event the stock is past the second lightresponsive device 13, as shown in Fig. 1, when the lamps flash, only the devices 14 and 15 will be operated. This will result in only resistors 42 and 43 being placed in the field circuit 44, and if past device 14, only clevice'15 and resistor 43 will be placed in service. I Should the stock be in step with the shear when it passes under the, first light- .responsive device 12, the speed of the feed table will not be altered as the stock in such event will be beyond or under the last light-responsive device by the time the lamps are flashed, so that none of the light-responsive devices 13, 14 and 15 will be operated.

With the passing of the trailing end of the stock over the first light-responsive device 12, such device isoperated to open the circuit25, and'this in opening opens the contactor 26' which deenergizes the circuits 27 and 28 and places the system in readiness for operation on the next succeeding piece of stock to be fed to the shear.

Among the advantages of this invention, it provides a very simple, inexpensive and easily installed, as well as dependable control for regulating the operation of a flying shear so as to control the first cut which a shear will produce on a piece of stock fed to it at random. As will be readily appreciated by those skilled in the art, the invention is particularly applicable to shears of the type illustrated which are provided with a plurality of cutting blades for shears having similar operating characteristics. This is especially true where such shears are adapted to miss cuts to provide the length of cuts desired as disclosed in thepresent inventors copending application Serial No. 676,313, filed June 17, 1933 When applied to shears of this character, as will be appreciated, the length of the first cut is reduced to a fraction of the distance between the ,cutting blades, such fraction at a maximum being equal to the distance between the cutting blades divided by the number of light-responsive devices employed for varying the speed of the feeding mechanism used with the shear.

According to the provisions of the patent statutes, I have explained the. principle and mode of operation of my invention, and have illustrated and described what I now consider to represent its best embodiment. However, I desire to have it understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically illustrated and described.

'I claim: v

1. In combination with means for feeding an elongate web into a flying shear or like work device, means for driving said feeding means, means responsive to the web and shear for varying thespeed of the driving means, and other means responsive to the web for controlling the extent of operation of said speed-varying means.

2. In combination with a flying shear or like work device, means for feeding an elongate web into said work device, means for varying the speed of said feeding means, means jointly responsive to said web and said work device for setting said speed-varying means in operation, and other means responsive to the web for controlling the extent of operation of said speedvarying means.

3. In combination with a continuously actuated flying shear or like work device adapted to operate at regular intervals upon a piece; of web, means for feeding web to said work device, means for varying the speed of said feeding means, means jointly responsive to said web and said work device for setting said speed-varying means in operation, and other means responsive to the web for rendering said web and work-device responsive means operative and also controlling the extent of the operation of said speed-varying means.

4. In combination with a flying shear, means ,for feeding pieces of web into said shear, means for feedng pieces of web into said shear, means for varying the speed pf said feeding means, a series of stock-responsive devices arranged in spaced relation in the path of said stock over a distance equal to the distance said web normally travels between cuts of the shear, means operated in synchronism with said shear arranged to cooperate with said stock-responsive means for controllingthe placing in operation of said speed-varying means, and means responsive to one-of said stock-responsive means for controlling the period of operation of said speed-varying means and also the period of operation of said other stock-responsive means.

6. In combination with a continuously operated flying shear equipped with cutting blades,

means for feeding pieces of elongate stock into said shear, a series of stock-responsive devices arranged in uniform spaced relation in the path of the stock over a distance equal to the distance the stock is normally fed between-cuts of said shear, means for varying the speed of said stockfeeding means, means selectively responsive to said stock-responsive means and a control device operated by said shear in timed relation with said cutting bladesfor controlling the setting in operation of said speed-varying means, and means responsive, to the first of said stockresponsive means to be actuated by the stock for controlling the period of operation of said speedvarying means.

7. In combination with a flying shear, means for feeding stock into saidshear, means for varying the speed of said stock-feeding means, means for controlling the operation of said speedvarying means comprising a series of light-re sponsive devices arranged in the path of the stock and uniformly spaced over a distance equal to the distance the stock normally travels between cutting operations of the shear, a continuously illuminated lamp mounted on the opposite side of the stock from the one of said devices disposed the farthest from the shear, lighting means for projecting light rays into said other light-responsive devices, means operated by theshear for causing said latter lighting means to flash each time the shear is operated to produce a cut, means set in motion when a piece of stock moves between said first-mentioned lamp and light-responsive device for rendering said other lighting means operable under the control of said shear operated light-flashing means and also controlling the period of time said latter light-responsive device exercises a control over said speed-varying means, and means operated by the light-responsive devices spaced from said first light-responsive device when operated by said shear controlled lighting means for controlling said speed-varying means.

8. In combination with a flying shear equipped with cooperating cutting elements, means for feeding elongate web into said shear, web-responsive means disposed along the path of said web between points separated a distance effectively equal to substantially the distance the web normally travels between cuts, and means controlled by said web-responsive means for so varying the delivery of the web to the shear as to thereby synchronize the entrance into the shear of the leading end of the web with the movement of said cutting elements into cutting opposition.

9. In combination with a flying shear equipped with cooperating cutting elements, means for feeding web material into said shear, web-responsive means disposed along the path of said feeding means between points separated a distance effectively equal to the peripheral distance between said cutting elements, and means controlled by said web-responsive means for so varying the delivery of the web to the shear as to thereby synchronize the entrance into the shear of the leading end of the web with the movement of said cutting elements into cutting opposition.

10. In combination with a flying shear, means for feeding web material thereinto, means for varying the speed of said feeding means, a plurality of stock responsive elements arranged in the path of the Web and operative along the length thereof, and means responsive to the shear cooperating with said stock responsive means for controlling the operation of said speed varying means to thereby control the length of the first cut.

11. In combination with a continuously operable flying shear equipped with cooperating cutting elements, means for feeding web material into said shear, means for modifying the delivery of the web to the shear, Web responsive means disposed at the entry side of the shear and operative along the length of the web over a distance eifectively equal to the length of the cuts normally made by the shear, and means responsive to the shear cooperating with said web responsive means for controlling the operation of said delivery modifying means to thereby control the length of the first out.

12. In combination with a flying shear, means for delivering web material into said shear, means for modifying the delivery of the material to the shear, a plurality of stock responsive elements arranged along the delivery path of the material, and means responsive to the shear cooperating with said stock responsive elements for controlling the operation of said delivery modifying means to thereby control the length of the first cut.

FLORENCE C. BIGGERT, JR. 

